1. Field of the Invention
The present invention generally relates to the field of packaging integrated circuit devices, and, more particularly, to a carrierless chip package for integrated circuit devices, and various methods of make same.
2. Description of the Related Art
Microelectronic devices generally have a die (i.e., a chip) that includes integrated circuitry having a high density of very small components. In a typical process, a large number of die are manufactured on a single wafer using many different processes that may be repeated at various stages (e.g., implanting, doping, photolithography, chemical vapor deposition, plasma vapor deposition, plating, planarizing, etching, etc.). The die typically include an array of very small bond pads electrically coupled to the integrated circuitry. The bond pads are the external electrical contacts on the die through which the supply voltage, signals, etc. are transmitted to and from the integrated circuitry. The die are then separated from one another (i.e., singulated) by backgrinding and cutting the wafer. After the wafer has been singulated, the individual die are typically “packaged” to couple the bond pads to a larger array of electrical terminals that can be more easily coupled to the various power supply lines, signal lines and ground lines.
Electronic products require packaged microelectronic devices to have an extremely high density of components in a very limited space. For example, the space available for memory devices, processors, displays and other microelectronic components is quite limited in cell phones, PDAs, portable computers and many other products. As such, there is a strong drive to reduce the height of a packaged microelectronic device and the surface area or “footprint” of a microelectronic device on a printed circuit board. Reducing the size of a microelectronic device is difficult because high performance microelectronic devices generally have more bond pads, which result in larger ball/grid arrays and thus larger footprints.
FIGS. 1A-1B are, respectively, a cross-sectional and top view of an illustrative packaged integrated circuit (IC) device 10. The packaged IC device 10 is comprised of an integrated circuit chip 12 that is affixed to a carrier 14 by an adhesive material 18. The chip 12 and carrier 14 comprise a plurality of bond pads 20 and 22, respectively. A plurality of wire bonds 24 conductively couple the bond pads 20 on the chip 12 with the bond pads 22 on the carrier 14. Also depicted in FIG. 1A is a conductive structure 28, such as a printed circuit board, a motherboard, a memory module, or the like. The conductive structure 28 typically comprises a plurality of insulated traces (not shown) and a plurality of bond pads 30. In one illustrative embodiment, the chip 12 is conductively coupled to the conductive structure 28 by a plurality of solder balls 30. The chip 12 is encapsulated with a molding or epoxy compound 16.
FIG. 1B is a top view of the device 10 with the epoxy compound 16 removed. As shown therein, the bond pads 22 on the carrier 14 occupy a lot of space. The presence of the bond pads 22 can, in some cases, cause the carrier 14 to delaminate. Such delamination can cause the chip 12 to fail or at least not perform up to its full capabilities. Moreover, the packaged IC device 10 can be relatively large due to its basic configuration, the components involved, and the manner in which it is fabricated. For example, the distance 11 between the edge of the chip 12 and the edge of the epoxy compound 16 may range from approximately 0.5-1.0 mm. The carrier 14 may have a thickness that varies from approximately 125-450 μm, depending on the application and the composition of the carrier 14. Similarly, the thickness of the epoxy compound 16 may also vary, e.g., from approximately 0.5-1.2 mm. Thus, the overall height 13 of the carrier 14 and epoxy compound 16 may range from approximately 0.40-1.65 mm.
The present invention is directed to a device and various methods that may solve, or at least reduce, some or all of the aforementioned problems.